var card_game=document.getElementById("card_game");
var btn_num=document.querySelectorAll(".btn").length;

//事件代理
card_game.addEventListener("click",function(e){
	if(e.target.className.indexOf("btn")!=-1){
		var lv=e.target.id;
		//页面跳转
		window.location.href="./src/html/card.html?lv="+lv+"&btn_num="+btn_num;
	}
})